FOBT test checks of hidden blood in the stool samples. The Fecal occult blood test (FOBT) is used to indicate polyps or cancer in the rectum or in the colon, however, not all polyps or cancers bleed. It is used to diagnose several conditions that can impact the digestive tract. Blood in stools is a serious condition, as it could be a symptom of a potentially harmful disease other than the colon cancer, according to a recent research. Generally this test repeats once in every year.
FOBT Test – Results
A positive diagnosis in the FOBT test indicates bleeding at some point in the digestive tract. It means the stool sample contained blood. Positive diagnosis in the FOBT test is so common that about 1 in 14 people have it. Many conditions may cause bleeding such as inflammation, hemorrhoids, and polyps, and they are not always associated with cancer.
The FOBT test is very accurate, with the accuracy of the 6-sample FOBT being 93.9%, and that of the single digit FOBT being 97.5%.
Reasons for Blood in Stool
Following are the most frequent reasons for blood in a stool sample. Generally this blood loss is due to:
- Swallowed blood from nosebleeds or bleeding gums
- Ulcerative colitis
- Anal fissures
- Infections in the intestine that lead to inflammation
- Haemorrhoids (Piles)
- Inflammatory bowel disease
- Early stage bowel cancer
- Crohn’s disease
- Colitis – an inflammatory bowel disease
- Blood vessels’ abnormalities in the large intestine
- Diverticular disease due to outpouching of the wall of the colon
Limitations and Risks of the FOBT Test
Limitations and risks of the FOBT test are as follows:
- The results of the FOBT test are not always accurate. It is possible for the FOBT test to conclude negative diagnosis, even when the cancer is present, that is a false-negative result. This can be the case when the polyps or cancers do not bleed.
- If the diagnosis in the FOBT test is positive, the physician can suggest a test to analyze the inside of the colon, for instance, a colonoscopy.
FOBT Test Diagnosis Early Stage Bowel Cancer
FOBT test diagnoses bowel cancer in its initial stages. However, a positive result in this test does not always indicate the patient has bowel cancer. Other abnormalities such as hemorrhoids or ulcers are most common reasons for a positive result in this test. Healthcare providers have to to conduct more tests to determine the cause.
Many problems can result in bowel cancer, such as high consumption of alcohol, polyps, smoking tobacco, obesity, processed meat consumption, inflammatory bowel disease, for instance, Crohn’s disease, family history, and genetic risk.
Bowel cancer affects the digestive system, including the small and large intestines. In fact, colorectal cancer is the 3rd most common cause of cancer-associated deaths in the USA, among both women and men.
Certain Medications Affect the Outcomes of the FOBT Test
Certain medication may also result in a false-positive diagnosis in the FOBT test. These medications include nonsteroidal anti-inflammatory drugs, oral anticoagulants, and antiplatelet agents, for instance, low-dose aspirin can cause a false positive in the FOBT test because of the insignificant losses in the gastrointestinal tract.
FOBT Lab Test Diagnosis Hemorrhoids
Hemorrhoids cause swollen veins in the lower rectum region. Internal hemorrhoids do not cause any pain, but they cause internal bleeding. The external hemorrhoids cause pain. The other name for hemorrhoids is piles. They are swollen veins in the lower rectum and anus region that appear the same as varicose veins. Hemorrhoids cause internal bleeding in bowel movement. The stools have a tarry or maroon color, which is a symptom of bleeding.
Other disorders may cause similar symptoms as hemorrhoids, such as abnormal vessels for blood in the colon, colorectal cancer, colon polyps, anal fissures, or diverticulosis. Diverticulosis weakens the lining of the colon and makes it form small pouches.
The reason for hemorrhoids is an increased pressure in the lower region of the rectum. This can result from various stimuli such as regular lifting of heavy weight, low-fiber diet, obesity, pregnancy, chronic constipation or diarrhea, strain during bowel movements.
The discharge of mucus occurring with certain hemorrhoids can make the patient feel as if they have not emptied their rectum fully, after a bowel movement. In other cases, the hemorrhoids form around the anus. They are called external hemorrhoids. External hemorrhoids can collect surplus blood, cause intense pain, and develop clots.
FOBT Test – Preparation
The FOBT test requires preparation as certain foods can stimulate false alarms. These foods include all red meat, broccoli, carrots, beets, cauliflower, cantaloupe, grapefruits, cucumbers, radishes, mushrooms, turnips, and horseradish.
Types of Fecal Occult Blood Tests
The different types of the fecal occult blood tests are as follows:
- Immunochemical fecal occult blood test (FIT or iFOBT)
The method for collecting samples for this test varies among manufacturers, however, specific devices, such as a special spoon helps collect a specimen of stool and to store it in a container. This immunochemical fecal occult blood test method is preferable over the guaiac fecal occult blood test as it is extra sensitive. Moreover, it does not need any restrictions on diet before testing and specimen collection as testing is frequently performed on a random sample of stool.
- Flushable tissue or reagent pad
- Guaiac fecal occult blood test (gFOBT)
Other Tests for Colorectal Cancer
Other tests for colorectal cancer include the FIT-DNA test or the stool DNA test. These tests diagnose colorectal cancer in its early stages. Moreover they detect the cellular changes that indicate pre-cancerous or cancer polyps. Moreover, this test can identify blood in the stool.
Colorectal Cancer – Symptoms and Causes
One of the distinguishing signs of colorectal cancer is blood in the stool. This cancer causes abdominal pain, cramps, and aches that do not go away. Moreover, the patient loses weight, and experiences constipation, diarrhea, or constantly feels that the bowel is not empty.
Many health conditions can lead to colorectal cancer. The factors that result in colorectal cancer include older age, inflammatory intestinal conditions, inherited conditions that increase the risk of colon cancer, high-fat, low-fiber diet, a sedentary lifestyle, family history of polyps or colorectal cancer. Moreover, people of African-American race are genetically more vulnerable to colorectal cancer.
Colonoscopy After The FOBT Test
Colonoscopy procedures often follow the FOBT test. It is a minor surgery in which the patient initially gets a mild sedative that helps them relax. The healthcare practitioner uses a thin tube to search inside the colon. The tube is a flexible fibre-optic device with a camera called scope. Colonoscopy tests are often used to check the signs such as polyps, bleeding, as well as other symptoms of colon cancer. Colonoscopy does not cause any pain to the patient as they receive a sedative before the start of the procedure. These sedatives make them sleepy so they do not generally remember or feel anything about the procedure.
FOBT Test at Labwork, Houston
FOBT test is available at Labwork, Houston. Labwork is an approved medical diagnostic lab based in Houston. If you live in Houston, you can also order a mobile phlebotomy service and have samples collected from your home. An expert phlebotomist from the lab will visit you to collect the sample for testing.
How often do you need to do the fecal occult blood test?
A colonoscopy is the best method to diagnose colorectal cancer. If this test is not performed as required, then you must get a FOBT lab test each year, starting at the age of 45 years. FOBT lab tests can also be conducted in addition to a flexible sigmoidoscopy once in every 5 years to check for cancer or colorectal polyps..
How much blood should be present in the stool for positive diagnosis in the FOBT test?
Small quantities of blood are normally present in the stool, the occult blood test detects larger quantities of blood in the stool.